2005.09.26 14:58 "RE: [Tiff] Additional Lossless Compression Schemes", by Jason Frank

For bitonal images, I'd love to see JBIG2 support http://www.jpeg.org/jbig/jbigpt2.html. It can either be lossless or lossy, and supposedly is 3 to 5x smaller than G4/MMR. Of course, I take that with a grain of salt. It's currently supported inside of the Acrobat spec (v 1.5?) and there is an open source decompression library already http://jbig2dec.sourceforge.net/, although it's still in alpha stages.

Any thoughts on this?

Jason

-----Original Message-----

From: tiff-bounces@lists.maptools.org [mailto:tiff-bounces@lists.maptools.org] On Behalf Of Frank Warmerdam

I was wondering if there is much interest in adding more lossless compression schemes in libtiff.

In addition to Packbits (pretty crappy) we have LZW and the more recent Deflate. My understanding is that Deflate is usually better than the old LZW though not as widely supported. Also, that Deflate is essentially the "zip" compression type.

Since then I have seen "gzip" on Unix, but I am not clear if that is just deflate or not.

Then came bzip2 which seem 5-10% better in that gzip on many datasets.

Now looking around a bit I see LZMA which I have heard good things about.

   http://www.7-zip.org/sdk.html

Are there any opinions on possibly incorporating LZMA as an additional compression type?

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